Advances in understanding immune mechanisms of food protein–induced enterocolitis syndrome

Objective: This review provides an overview of our current understanding of the mechanisms of food protein–induced enterocolitis syndrome (FPIES). Data Sources: To capture recent articles published since our previous comprehensive review on the pathophysiology of FPIES, we performed a literature search through PubMed database, using the search terms FPIES and food protein–induced enterocolitis syndrome from 2016 to the current year. Study Selections: Studies in English containing biomarker or immune data were reviewed and summarized. Results: Studies of peripheral blood fail to exhibit evidence of antigen-specific humoral or cellular immunity underlying clinical reactivity to foods in FPIES. However, growing evidence suggests a robust systemic innate immune activation occurring during FPIES reactions and the activation of neuroendocrine pathways. Conclusion: FPIES reactions are associated with marked activation of innate immune and neuroendocrine pathways; however, the mechanism underlying the specific recognition of foods remains elusive.